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East China Sea (ECS) is an important climate modulator of East Asia. In the last glacial period, the global sea level, the path and strength of the Kuroshio Current experienced great changes; combined with the variable volume of fresh run-off input, they made the hydrographic situation in the ECS quite different from nowadays. Based on high-resolution alkenone-sea surface temperature (SST) and oxygen isotope composition of planktonic foraminifera Globigerinoides sacculifer we reconstructed paleo-sea surface salinity (SSS) of a long piston core DGKS9604 retrieved from the middle Okinawa Trough of the eastern ECS. The δ 18 O and SST records display significant variations with global ice volume. Synchrony of the millennial-scale climate events like YD and Heinrich events of core DGKS9604 to the ice core from the northern high latitudes, and the synchroneity of deglacial warming with the Bølling-Allerød warming suggests a strong coupling of the SST variations in the marginal Pacific Ocean to the climate of the North Atlantic, most likely through the Asian monsoon atmospheric circulation. The ECS documents lowest SST (22 °C) at ~ 26 cal kyr BP and ~ 3 °C SST difference between the full glaciation (26 to 19 cal kyr BP) and mid-to-late Holocene (6 cal kyr BP-present). The overall long-term hydrographic variations in the middle Okinawa Trough are controlled by temporal and spatial variations in: (i) the intensity and position of the Kuroshio Current, (ii) intensity of the Asian summer monsoon and (iii) sea-level fluctuations coupled with ECS topography. Saline surface water dominated over the middle Okinawa Trough during early pre-glaciation (37 to 31 cal kyr BP), last deglaciation (19 to 11.6 cal kyr BP), and mid-to-late Holocene (6 cal kyr BP-present), whilst freshened surface water prevailed during the late pre-glaciation (31 to 26 cal kyr BP), full glaciation (26 to 19 cal kyr BP) and early Holocene (11.6 to 6 cal kyr BP).

materials in dilute aqueous electrolytes, respectively, [7] although a common strategy for adjusting the operating window is to change the pH of the electrolyte. However, even in strongly alkaline electrolytes (pH = 14), hydrogen evolution still occurs at 2.213 V, which is too high to accommodate most of the anode materials desired by battery scientists. [8] Additionally, a downshift in O 2 evolution potential will occur simultaneously when the pH is increased, keeping the gap between the anodic and cathodic limits constant at 1.23 V. This gap, known as the electrochemical stability window in aqueous electrolytes under thermodynamic equilibria, is defined by the Pourbaix diagram. The slightly higher voltage gap of 1.8 V that has been realized in existing aqueous battery setups is the result of "kinetic overpotentials" of H 2 or O 2 evolutions, which depends on changing the salt concentration, catalytic activity of the electrodes, and applied currents. [9] As a result, very few suitable electrode materials have been reported for AIBs at present, and their energy densities are still far from those required for practical applications. A particular challenge is that O 2 or H 2 evolution will result in low energy efficiencies, which is of vital importance for this technology. [10] The working potential of lithium-ion battery electrode materials is also far beyond the thermodynamic stability limits of organic electrolytes. [11] Hence, solvent molecules coordinated with Li + to form solvation shells can suffer from decomposition when ions move between electrode surfaces during the charging/discharging processes. These decomposition reactions produce dense, solid products that deposit on electrode surfaces to form a solid-electrolyte interface (SEI), which prevents direct contact between the electrodes and electrolytes. [12] A large number of inorganic salts or precipitates originating from salt reductions may also be present in the SEI at the anode, making it insulating to long-range electron transport but conductive to ions. Therefore, it can prevent sustained electrolyte decomposition while still allowing electrochemical reactions to proceed. The presence of an SEI substantially expands the usable electrochemical stability window of nonaqueous electrolytes. [13] However, protective interfaces are not formed in conventional aqueous electrolytes, because the decomposition products from coordinated water mostly are gases such as H 2 and O 2 , which will escape from the electrolyte on formation. [2] Unfortunately, traditional inorganic lithium salts such as Li 2 SO 4 , LiCl, and LiNO 3 are stable enough to be reduced Aqueous lithium/sodium-ion batteries (AIBs) have received increasing attention because of their intrinsic safety. However, the narrow electrochemical stability window (1.23 V) of the aqueous electrolyte significantly hinders the development of AIBs, especially the choice of electrode materials. Here, an aqueous electrolyte composed of LiClO 4 , urea, and H 2 O, which allows the electrochemical stability windo...

Aqueous rechargeable Zn/birnessite batteries have recently attracted extensive attention for energy storage system because of their low cost and high safety. However, the reaction mechanism of the birnessite cathode in aqueous electrolytes and the cathode structure degradation mechanics still remain elusive and controversial. In this work, it is found that solvation water molecules coordinated to Zn2+ are coinserted into birnessite lattice structure contributing to Zn2+ diffusion. However, the birnessite will suffer from hydroxylation and Mn dissolution with too much solvated water coinsertion. Through engineering Zn2+ primary solvation sheath with strong‐field ligand in aqueous electrolyte, highly reversible [Zn(H2O)2]2+ complex intercalation/extraction into/from birnessite cathode is obtained. Cathode–electrolyte interface suppressing the Mn dissolution also forms. The Zn metal anode also shows high reversibility without formation of “death‐zinc” and detrimental dendrite. A full cell coupled with birnessite cathode and Zn metal anode delivers a discharge capacity of 270 mAh g−1, a high energy density of 280 Wh kg−1 (based on total mass of cathode and anode active materials), and capacity retention of 90% over 5000 cycles.